In a cellular mobile communication system, in order to achieve better service, a mobile communications terminal (such as a mobile phone) may search nearby cell signals when in an idle mode, and the terminal may select a cell site (e.g., a base transceiver station) with which to connect based on the strength of cell signals of the cell site. Each cell site may broadcast a location area (i.e., coverage area, which may be identified by a number) to which the cell site belongs in a system broadcast message. When the cell site selected by the terminal belongs to (i.e., corresponds with) a new location area, the mobile terminal may initiate a location update process to report the change in location area, together with the location area number of the cell site with which the mobile terminal was previously connected, to the network.
A “pseudo base station” is an “illegal” cell site (i.e., a cell site that is not directly or indirectly authorized by the user for connection to the mobile terminal, and which may or may not be in violation of applicable laws and regulations) that is not in the mobile communication network of the user's telecom operator. Some pseudo base stations are set up to seek connections with mobile terminals within range so that the pseudo base station can feed short “annoying” messages (i.e., undesirable messages like advertisements, scamming or phishing messages, spam, malware, etc.) to the terminals. The annoying messages are normally “short” (i.e., limited in quantity of text and/or size of images) for greater effectiveness: shorter messages are more easily transmitted to mobile terminals (i.e., are transferred in less time and/or require less bandwidth), and do not require as much of the user's time to impart the information contained in the message (before the user decides that the message should be ignored and/or discarded). To induce mobile terminals to select it, the pseudo base station may enhance its transmission power so that it has stronger signal strength relative to other cell sites and is thus more likely to be selected by mobile terminals in its coverage area (i.e., within range). Once a mobile terminal has connected to the pseudo base station (and updated its location area with the network), the “pseudo base station” may transmit unauthorized and unsolicited short messages with undesirable content to the mobile terminal.